Hello there @Mili2016!
Thank you for reaching out to us through our Community Forums about your security passcode. I understand how important it is to have this straightened out. I will be more than happy to provide you with the tools needed to get this taken care of.
You can absolutely reset your PIN online. Our Reset Security Passcode article will be very helpful in doing this. Just enter the requested information and you will be on your way in no time.
If you run into trouble resetting this on our website, don’t worry, you can also take advantage of our online chat services to speak with an agent. Another option is to take your photo ID into any AT&T Store and have it reset there as well.
I hope this information is helpful, let me know if you have any further questions or concerns. Happy New Year!
Bradilynn, AT&T Community Specialist